The present disclosure relates to a multi-layer electrophotographic photosensitive member, a process cartridge, and an image forming apparatus.
An electrophotographic photosensitive member is used as an image bearing member in an electrographic image forming apparatus (for example, a printer or a multifunction peripheral). Typically, the electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer can contain a charge generating material, a charge transport material (for example, a hole transport material or an electron transport material), and a resin (binder resin) for binding the charging generating material and the charge transport material together. An electrophotographic photosensitive member including a photosensitive layer such as above is called an organic electrophotographic photosensitive member. The photosensitive layer may include a charge generating layer having a charge generating function and a charge transport layer having a charge transporting function. An electrophotographic photosensitive member such as above is called a multi-layer electrophotographic photosensitive member.
One known example of the hole transport material for transporting holes that is applicable to a multi-layer organic electrophotographic photosensitive member is a tris(4-styrylphenyl)amine derivative.